Nunes' memo, McCabe's ouster, and Mueller's next move: Inside the most dramatic week of the Russia investigation

In what was perhaps the most momentous week in the Russia investigation so far, headlines were dominated by the release of a highly controversial memo by Republicans on the House Intelligence Committee. The document's central claim is that the Department of Justice and FBI bypassed proper protocol when they sought a warrant to surveil Carter Page, a former adviser to President Donald Trump's campaign.

Earlier in the week, FBI deputy director Andrew McCabe announced that he was leaving the bureau, and Trump's former legal spokesman geared up to implicate a key member of Trump's inner circle in the special counsel Robert Mueller's Russia investigation.

Meanwhile, the heads of three of Russia's top spy agencies — two of whom are sanctioned — traveled to the US last week, just days before the Trump administration declined to enforce sanctions on Russia as a penalty for meddling in the 2016 presidential race.

Nunes comes under fire again: Rep. Adam Schiff, Nunes' counterpart on the House Intelligence Committee, claimed the chairman made "material changes" to the version of the memo the committee sent to the White House for review. Meanwhile, Nunes refused to answer questions about whether he coordinated with the White House while drafting the memo.

McCabe is out: Deputy director Andrew McCabe left the bureau on Monday, reportedly amid a Justice Department investigation into his handling of the Clinton email investigation. While FBI director Christopher Wray stressed that McCabe's ouster was not politically motivated, McCabe's defenders questioned the move and wondered whether Wray had caved to pressure from Trump and Attorney General Jeff Sessions, both of whom had either publicly or privately urged him to replace McCabe.

Rosenstein and Mueller are in the hot seat: Trump, who said the memo was a "disgrace" to top leadership at the FBI and DOJ, is expected to use the document to further discredit Mueller's Russia investigation. Deputy attorney general Rod Rosenstein, who oversees the investigation, could also be in hot water — asked Friday whether he still had confidence in Rosenstein, Trump replied, "You figure that one out." A White House official later walked back his comments, however, and said the president had no intention of firing Rosenstein .

Mueller homes in on the Trump Tower Russia meeting: Mueller's team has requested to interview Mark Corallo, the former spokesman for Trump's legal team. Mueller is likely to ask Corallo about the events leading up to his resignation, which took place shortly after Trump crafted a misleading statement in response to reports that his son met with a Russian lawyer offering dirt on Clinton in June 2016, at the height of the campaign.

Hope Hicks draws scrutiny in the obstruction case: When he interviews with Mueller, Corallo reportedly plans to tell the special counsel that White House communications director Hope Hicks may have hinted at concealing crucial emails related to the Trump Tower meeting while on a conference call with him and Trump last July.

Trump's lawyers devise a new strategy: Trump's lawyers are planning to argue that Mueller has not met the required standard to merit a face-to-face interview with the president. The strategy is one of several options Trump's personal defense lawyers, John Dowd and Jay Sekulow, are examining as they seek to limit or avoid an interview with Mueller altogether, but experts say it's unlikely Mueller will agree to anything other than a face-to-face sit down with Trump.

US clears three top Russian spy chiefs to enter the country: Days before the White House declined to enforce sanctions on Russia, the US allowed three top Russian intelligence officials — two of whom are sanctioned — into the country. Two of the officials met with CIA director Mike Pompeo to discuss counterterrorism, and it's unclear what the purpose of the third official's visit was.